This invention relates generally to apparatuses for installing overhead conductor wires above and along railroads and more particularly to a wheeled, overhead wire installing apparatus for installation of overhead conductor wires of electrified railroads.
In wire installation of this kind known heretofore, any set or tendency of an overhead wire, such as a trolley wire, drawn out of a drum to retain its coiled curvature is removed by imparting to a certain extent a stretching tension to the wire. In this case, the trolley wire drawn out from the drum is led out through an overhead wire guide roller mechanism, which has a horizontal transverse guide roller which bears the trolley wire and vertical guide rollers for guiding the trolley wire from the two lateral sides. Unless the diameters of these guide rollers are large, a firm permanent set in bending in the horizontal and vertical directions will be imparted to the trolley wire thus guided over the circumferential surfaces of the guide rollers and led out. However, if diameters of the guide rollers are made large enough to avoid this permanent bending set, the guide roller mechanism will become tremendously large and with be impractical.
In order to solve this problem, an overhead wire guide roller mechanism in which a large number of guide rollers of small diameter are so arranged that, in combination as a whole, they form a horizontal guide surface and a vertical guide surface of large radii of curvature has been proposed as disclosed in the specification of Japanese Utility Model Application Laid Open No. 121795/1976. In this guide roller mechanism, since guide surfaces of large radii of curvature are formed by small-diameter guide rollers, there is afforded an advantage in that a small-size mechanism provides guide surfaces of large radii of curvature.
In this guide roller mechanism, however, since the entire guide roller mechanism is provided in an immobile state, variations occur in the angle with which the trolley wire is introduced into the guide roller mechanism, when the mechanism is raised or lowered, thus changing the difference between the heights of the trolley wire supply drum and the guide roller mechanism. As a consequence, even if the guide roller mechanism is adjusted in a certain state, the attitude of the horizontal guide surface of the guide roller mechanism will become unsuitable as the work platform supporting the guide roller mechanism ascends and descends, whereby undesirable bending sets or deformations will be imparted to the trolley wire.
On one hand, since this guide roller mechanism is mounted on the same car as the trolley wire drum from which the trolley wire is drawn out, the size of the work platform supporting the guide roller mechanism is limited, whereby the work efficiency is relatively low.